Constant-current heating devices for fixed window seals

ABSTRACT

This device for electrically heating a wire embedded in the molding strip of a fixed window, such as a windshield or the like, for sealing same to the surrounding frame, comprises a movable supply cabinet, a voltage regulator for maintaining a constant current value in said wire, a data processing unit comprising members adapted to deliver orders of an instantaneous or delayed-action nature for controlling in succession preheating and heating control circuits for energizing said wire during two different time periods, and safety members controlling the current value in said wire and the voltage across the terminals through which said wire is connected to the device. This device is applicable to automotive construction and also to building construction.

[22] Filed:

States Patent Ferrand et al.

[ 1 Aug. 29, 1972 [54] CONSTANT-CURRENT HEATING DEVICES FOR FIXED WINDOWSEALS [72] Inventors: Andre Ferrand; Michel Bonnefont,

both of Billancourt, France [73] Assignees: Regie Nationale des UsinesRenault, Billancourt; Automobiles Peugeot, Paris, France March 31,1971[2i] Appl. No.: 129,822

30 Foreign Application Priority Data April 10, 1970 France ..-.70/130os52 U.S.Cl. ..219/482,2l9/498,2l9/501 51 Int. Cl. ..H05b 3/02 [58] Fieldof Search ..219/482, 203, 483, 501, 498, 219/485, 486, 490, 509, 522;263/3 [56] References Cited UNITED STATES PATENTS 3,560,712 2/ 1971Toohill ..219/483 3,465,126 9/1969 Blumenkranz ..219/482 PrimaryExamineF-Bemard A. Gilheany Assistant Examiner-F. E. BellAttorney-Stevens, Davis, Miller & Mosher [57 ABSTRACT This device forelectrically heating a wire embedded ous or delayed-action nature forcontrolling in succession preheating and heating control circuits forenergizing said wire during two different time periods, and safetymembers controlling the current value in said wire and the voltageacross the terminals through which said wire is connected to the device.

This device is applicable to automotive construction and also tobuilding construction.

7Claims,4DrawingFigures P'A'TENTED I912 3.688.078 SHEET 2 [IF 3 FIXEDWINDOW SEALS This invention relatesto a device for heating the sealingor moulding strips, incorporating a heating wire element, of fixedwindows.

This invention is concerned more particularly with a device adapted toheat by Joule effect and giving a constant amount of heat per unitlength of the seal (for a given constant cross-section of the resistancewire) while taking due account of any defects or failures likely tooccur during the heating operation.

This invention further relates to the application of this device to thesealing of windscreens of motor vehicles by resorting to the knownmethod consisting in applying a voltage to a metal wire covered with, orembedded in, a tube of rubber or thermosetting plastic material, inorder to heat this tube so that the curing thereof will seal thewindscreento its frame.

It is thus clear that the heating effect is obtained by using anelectric resistance embedded in the seal or moulding as it is extrudedor otherwise produced.

A method is already known wherein the seal or moulding is heated in twodifferent time periods, i.e. a first, relatively short preheating periodand a second, relatively longer heating period, a transfonner being usedfor adapting the mains voltage to a specific value for a well-definedseal or wire length. This transformer can deliver a plurality ofsecondary voltages to permit the heating of seals of different lengths,but in this case some means must be provided for displaying the type ofvehicle or the seal length.

The main inconveniences characterizing this known method may be listedas follows: X

a. it applies to a specific seal length, so that it is not possible toadmit different types of vehicles on the same production line withoutany preliminary display, thus implying additional operations and anincreased possibility of error;

b. it is a source of poor electric contacts, and the variations inlength of the seal or moulding have a direct bearing on the degree orquality of the curing;

c. since the maximum current is preset, the maximum permissible currentmust be reduced so that the current as a function of the variousparameters cannot exceed the permissible value, and therefore the lengthof the production line must be increased, since the quantity of heat isconstant and the current is lower, so that a longer heating time isrequired and the length to be attributed to the application unitassociated with the production line must also be lower;

(1. in case of short-circuit during the operation, which causes the fuseto melt, the intervention of an electrician is necessary.

It is the essential object of the present invention to provide a heatingdevice adapted to eliminate the various inconveniences set forthhereinabove, this device being furthermore characterized by thefollowing advantageous features:

i. it permits defining and reproducing with maximum fidelity a givenquality of seal vulcanization, irrespective of the variations in thesupply voltage, the value of the contacts connecting the moulding to thesource of current, etc...

. ii. the windscreens of different vehicles can be sealed in theirframes without modifying the adjustment iii. no restraint arises in caseof shorts or grounding of the connecting clamps iv. any possiblefailures are signaled positively by telltale or pilot lamps, and in thiscase the vehicle is directed to a retouch line 7 I v. the length of theassembly line may be calculated within very close limits.

Of course, the device of this invention is also applicable to thesealing of fixed windows in buildings, prefabricated wall panels, etc...in this case the method is highly advantageous due to the greatvariations in the lengths of the sealing mouldings and considering theimpossibility of previously displaying the necessary voltage. I

The device according to this invention for heating a seal or mouldingstrip having a metal resistance wire embedded therein and submitted tosuccessive preheating and heating periods, is characterized essentiallyin that it comprises in a movable supply cabinet or like unit a voltageregulating member adapted to maintain a constant current value in theseal wire irrespective of its length, a data processing unit forcontrolling the heating phase and comprising members adapted to deliverinstantaneous orders and delayed orders for controlling in successionthe preheating control circuit and the heating control circuit,respectively, so as to energize the resistance wire during two differenttime periods, and first and second safety members controlling the valueof the current delivered to said wire and the voltage across theconnecting terminals of said wire.

Other features and advantages of this invention will appear as thefollowing description proceeds with reference to a typical form ofembodiment of the heating device constituting the subjectmatter thereof,given by way example with reference to the attached drawings, in whichFIG. 1 is a diagrammatic elevational and cross-sectional view showing anassembly line in an automobile factory, where windscreens are fitted tothe vehicles, the section being taken along the line I-[ of FIG. 2

FIG. 2 is a plan view of one section of the assembly line of FIG. 1

FIG. 3 is a diagrammatic illustration, on a larger scale, of the supplycabinet, and

FIG. 4 is the wiring diagram of a data processing unit.

Referring to FIGS. 1 and 2 of the drawings it will be seen that anassembly line for the windscreens of motor vehicles carries vehicles V1,V2, V3, V, the resistance wire embedded in the moulding of thewindscreen of each vehicle is adapted to be energized through a heatingdevice D accompanying the vehicle. Each device D comprises, as shown inFIGS. 1 to 3, a movable cabinet C travelling on feed trolleys M of aclosed loop feed rail system G having an operating branch G and a returnbranch G This cabinet is connected to a supply cable A to which acontrol box B provided with a push-button 11 is attached. The cable Aemerging from the box B is connected to a pair of clamps P adapted to beconnected to the ends of the heating or resistance wire (not shown) ofthe seal or moulding J.

The assembly line may comprise any desired and suitable number ofdevices D and associated movable cabinets C. By way of example, threesuch devices are illustrated in the drawings, one device C being inoperation while the other two C and C travel on the return rail sectionG The supply cabinet C connected to the closed-circuit rail system Gthrough the medium of a travelling tap M comprises, as illustrated inFIG. 3, firstly a voltage regulator R for setting the intensity of thecurrent flowing through the wire resistance at a predetermined constantvalue, irrespective of the length of said wire and therefore of itsresistance. The cabinet C further comprises a data processing unit Tand, connected to this unit, safety members 15 and 16 adapted tointerpret the passage of current through the wire of seal J and thevoltage across the terminals of said wire, respectively, and a frontcontact 1 interposed in the energizing circuit of said wire.

The data processing unit T comprises the following circuits (FIG. 4-) 8Circuit 101 this circuit comprises in series, between the phase Ph andneutral N, for example, an electromagnet coil 1 adapted to actuate thefront contact 1 of the wire supply circuit, a delayed-action backcontact 8 and a front contact 9 actuated by electromagnet coils 8 and9/10, respectively.

Circuit 102 this circuit comprises an electromechanical timer adapted tocount or calculate the wire preheating time. This timer comprises amotor 2 driving cam means for actuating correspondingtimelag contactsand an electric clutch 3 actuating instantaneous contacts the motor 2 isconnected in series with its delayed-action back contact 2 and theclutch is connected in parallel with this assembly these elements arefollowed in series by a front contact 16 actuated by avariable-threshold, minimum-voltage relay 16, by a delayed-action frontcontact 14 actuated by an auxiliary contact 14, and by a front contact 3actuated instantaneously by said clutch 3, this contact 3 being alsoconnected in parallel with contact 9 of circuit 101 Circuit 103 itcomprises the motor 4 of an electromechanical timer exactly similar tothe preceding timer 2, 3 but providing a higher time-lag than motor 2.This motor 4 is mounted in series with its delayed-action back contact4, and a front contact 3 this assembly being connected in parallel withclutch 3 and a tell-tale or pilot lamp 6, and clutch 5 is connectedbetween the neutral and the common point of contacts 4 and 3 Whenlighted the pilot lamp 6 indicates that the heating is on.

Circuit 104 it comprises, connected in series between the phase and theneutral, a delayed-action front contact 2 actuated by the motor 2 and apilot lamp 7 signalling the end of the preheating period.

Circuit 105 this circuit includes, connected in series between theneutral and the phase, an electromagnet coil (already mentionnedhereinabove in connection with circuit 101) and a delayed-action frontcontact 4 actuated by said motor 4 and having connected across itsterminals the holding front contact 8 of coil 8.

Circuit 106 it comprises, connected in series between the neutral andthe phase, the coil 9 controlling the closing of the contacts of anauxiliary contact unit comprising mechanical locking means, a frontcontact 8 responsive to coil 8 and a back contact actuated by clutch 5,a manually operated push-button 11 neutral and phase a coil 10 forcontrolling the opening of the contacts of the auxiliary contact unit ofcircuit 106, and a front contact 5 responsive to clutch 5.

Circuit 108, 'it comprises, connected in series between-neutral andphase, a pilot light 12 and a front contact 9 responsive to coil 9 thepilot light 12 signals that the preceding cycle took place without anyincident.

Circuit 109 this circuit comprises in series between neutral and phase apilot light 13 showing that the voltage value is normal, and a frontcontact 16 actuated by the minimum-voltage relay 16.

Circuit it comprises in series between neutral and phase an auxiliarycontact unit 14 actuating the front contact 14 of circuit 102, and afront contact 15, responsive to a minimum-current relay 15 a pilot light17 showing that the current intensity in the resistance wire is normalthis pilot light 17 is connected across the terminals of the coil ofcontact unit 14.

The variable-threshold minimum-current relay 15 connected across theterminals of a shunt S inserted in the heating circuit of wire J isresponsive to the current flowing through the wire.

In case of faulty contact or of excessive wire length in comparison withthe characteristics of the current supply available, which would cause areduction in the current value, relay 15 is energized to open itscontact 15 put out pilot light 17 and de-energize the relay 14 todiscontinue the heating.

7 In case of short-circuit or stray resistance in parallel to the wireJ, causing a reduction in the voltage across the wire terminals, relay16 opens its contacts 16, and 16 thus putting out pilot light 13 anddiscontinuing the heating.

Whatever the failure occuring during the heating cycle, relays 15 and/or16 are de-energized.

The function of the data processing unit T is to permit an automaticcycle operation while providing the necessary safety measures forproperly causing the moulding strip J to adhere to its surroundingframe.

This apparatus operates as follows When the operator has connected theclamps P to the terminals of the wire embedded in moulding strip J,current is caused to flow through this wire. Contact 9 (circuit 101) wasclosed at the end of the preceding cycle and contact 8, controlling theend of the heating cycle proper is still inoperative thus, relay 1 isenergized and contact 1 is closed.

If the complete system operates normally the contact 16 is closedinstantaneously contact 14, also closes but with a certain time lag dueto the fact that the operator cannot obtain a perfect contact within azero time. Timer 2-3 begins its counting period the circuit is through9,, 14 and 16 The clutch 3 of timer 2-3 releases the other timer 4-5 byclosing contact 3 A contact 5 causes the contact 9 to drop by an impulsedelivered to coil 10 (circuit 107) the continuity of the circuit forholding the assembly 2-3, 3-4, 6 is obtained via contact 3 At the end ofthe count of timer 2-3 the pilot light 7 is energized via contact 2(circuit 104) and the operacontact 8 The circuit 101 of relay 1(energization of p the wire in mouldingstripl) is subsequentlyde-energized by the opening of contact 8 At the same time the closing ofcontact 8 re-closes the contacts of relay 9, which indicates thetriggering thereof without any incident, so that 'l. the operator isinformed through pilot light 12 (closing of contact 9 in circuit 108).that the cycle took place without any incident or failure I H. the nextcycle can be authorized by closing contact 9 (circuit 101).

However, the operator has not, disconnected the wire in seal J, so thatall the necessary requirements would be met for starting another heatingcycle, were it not for the contact unit 8 being held in its energizedcondition (circuit 105) and thus preventing this next cycle.

Relay 8 is not released until the supply circuits are cutoff on thereturn circuit G therefore necessarily at a time whenno heating wire isconnected to the ap paratus.

If a failure or other defect occurs during the heating period contacts14 or 16 (circuit 102), are opened automatically. Y

Contact 3 (circuit 102) then drops and since contact 9 (circuit 101) wasnot returned to its open position, the cycle cannot be resumed unless amanual operation takes place, and if the operator normally disconnectingthe wire in moulding strip J at the end of the heating cycle fails tosee the pilot light No incident 12 (Circuit 108) he will deliver orswitch the vehicle to a retouch line and restore the apparatus to itsnormal operating condition by re-energizing relay 9 by depressingpush-button 11 (circuit 106).

Pilot lights 13 (circuit 109 normal voltage) and 17 (circuit 110normalcurrent) are tell-tale devices to be used only for emergencypurposes.

Although the present invention has been described with reference to apreferred form of embodiment it will readily occur to those skilled inthe art that various modifications, variations and applications may becontemplated and embodied without departing from the basic principle ofthe invention as set forth in the appended claims.

What is claimed as new is 1 Device for heating the seal or mouldingstrip of fixed windows, said strip having embedded therein a metal wireadapted to act as an electric resistor and being firstly preheated andthen heated, for causing the window to adhere to its surrounding frame,characterized in that it comprises in a movable cabinet connected totravelling supply means a voltage regulating member adapted to maintaina constant current intensity in said wire, irrespective of the wirelength, a data processing unit controlling the heating operation andcomprising members issuing instantaneous orders and delayed-actionorders for controlling in succession preheating control circuits andheating circuits to ensure the energization of said wire during twodifierent time eriods, andfi and second safet me be s s 'd firs embercontro img the current vzi lue iii said w i re and said second membercontrolling the voltage. drop across the connecting terminals of saidwire.

'2. Device according to claim 1, characterized in that the membercontrolling the current value in said wire is a minimum-currentrelay'inserted in the supply circuit of said wire and adapted to actuatethrough a front contact a first auxiliary contact unit comprising adelayedaction contact controlling in turn all the heating controlcircuits.

3. Device according to claims 2, characterized in that the membercontrolling the voltage drop acrossthe terminals of said wire comprisesa minimum-voltage relay having a front contact adapted to controlinseries with said delayed-action contact all the heating controlcircuits.

4. Device according to claim 1, characterized in that the preheatingcontrol circuit comprises a first circuit including a motor in serieswith a delayed-action back contact responsive thereto, and a secondcircuit in parallel with the first circuit and comprising a clutch foractuating a pair of instantaneous contacts.

5. Device according to claim 4, characterized in that the heatingcontrol circuit comprises a first circuit incorporating a motor inseries with a delayed-action back contact responsive thereto and asecond circuit parallel to said first circuit and comprising a clutchfor actuating another back contact and a front contact, the assembly ofsaid last-named motor and clutch being connected in series with a fromcontact responsive to said preheating control circuit clutch; and, arninimumvoltage relay having a front contact, the two heating circuitsbeing connected in parallel and inserted in the supply mains in serieswith the front contact on said minimum-voltage relay and also with afront contact responsive to the preheating clutch.

6. Device according to claim 5, characterized in that the contactresponsive to said clutch of said heating control circuit are adapted tocontrol the energization of the coil of another auxiliary contact unithaving a front contact adapted to control in turn the energization of acontrol relay inserted in the circuit connected to said wire, in serieswith a delayed-action back contact actuated by a third auxiliary contactunit responsive to a delayed-action front contact actuated by the motorof said heating control circuit.

7. Device according to claim 6, characterized in that a push-button isadapted to energize the coil controlling the actuation of said secondauxiliary contact unit.

1. Device for heating the seal or moulding strip of fixed windows, saidstrip having embedded therein a metal wire adapted to act as an electricresistor and being firstly preheated and then heated, for causing thewindow to adhere to its surrounding frame, characterized in that itcomprises in a movable cabinet connected to travelling supply means avoltage regulating member adapted to maintain a constant currentintensity in said wire, irrespective of the wire length, a dataprocessing unit controlling the heating operation and comprising membersissuing instantaneous orders and delayed-action orders for controllingin succession preheating control circuits and heating circuits to ensurethe energization of said wire during two different time periods, andfirst and second safety members, said first member controlling thecurrent value in said wire and said second member controlling thevoltage drop across the connecting terminals of said wire.
 2. Deviceaccording to claim 1, characterized in that the member controlling thecurrent value in said wire is a minimum-current relay inserted in thesupply circuit of said wire and adapted to actuate through a frontcontact a first auxiliary contact unit comprising a delayed-actioncontact controlling in turn all the heating control circuits.
 3. Deviceaccording to claims 2, characterized in that the member controlling thevoltage drop across the terminals of said wire comprises aminimum-voltage relay having a front contact adapted to control inseries with said delayed-action contact all the heating controlcircuits.
 4. Device according to claim 1, characterized in that thepreheating control circuit comprises a first circuit including a motorin series with a delayed-action back contact responsive thereto, and asecond circuit in parallel with the first circuit and comprising aclutch for actuating a pair of instantaneous contacts.
 5. Deviceaccording to claim 4, characterized in that the heating control circuitcomprises a first circuit incorporating a motor in series with adelayed-action back contact responsive thereto, and a second circuitparallel to said first circuit and comprising a clutch for actuatinganother back contact and a front contact, the assembly of saidlast-named motor and clutch being connected in series with a frontcontact responsive to said preheating control circuit clutch; and, aminimum-voltage relay having a front contact, the two heating circuitsbeing connected in parallel and inserted in the supply mains in serieswith the front contact on said minimum-voltage relay and also with afront contact responsive to the preheating clutch.
 6. Device accordingto claim 5, characterized in that the contact responsive to said clutchof said heating control circuit are adapted to control the energizationof the coil of another auxiliary contact unit having a front contactadapted to control in turn the energization of a control relay insertedin the circuit connected to said wire, in series with a delayed-actionback contact actuated by a third auxiliary contact unit responsive to adelayed-action front contact actuated by the motor of said heatingcontrol circuit.
 7. Device according to claim 6, characterized in that apush-button is adapted to energize the coil controlling the actuation ofsaid second auxiliary contact unit.